Luna

Terri Hawkes played a character named Serena in an episode of Disney’s Hercules in the episode Hercules and the Prom. Now this seems odd to me since Miss Hawkes is based in Toronto and the Hercules show was I’m pretty sure recorded in the states. And what are the odds Disney would fly her down for an joke on some show they weren’t part of (and yes I know DiC used to be part of Disney and Buena Vista released select episodes on VHS but I’m pretty sure the partnership ended before 1998. )

But I did watch the alleged episode and there was no character named Serena in the episode and if she voiced any female character in the episode it seemed doubtful as Hawkes has a fairly unique voice.

There was a character named Serena in the live action Hercules series that ran at the time but she definitely was not played by Miss Hawkes.

Luna Crescens

I have no idea, but it may have been genuine trolling that took a mind of its own.

I remember all the way back twenty years ago, someone uploaded a midi of "The Final Countdown" and listed is as the ending theme to a certain video game; it took quite a while for that rumor to be thoroughly debunked, not because it was that hard to do, but because it had grown legs and before high-speed Internet and the increased storage spaces, the only way to prove it was to see it for yourself.

IMDb used to allow regular users to submit credits for actors (it still may allow it, but I haven't been a regular visitor since they shut down their boards) so someone might have put it in there as a joke, and no one bothered to look at it.